Preparation and Characterization of SPEEK–PVA Blend Membrane Additives with Colloidal Silica for Proton Exchange Membrane Fuel Cell

Abstract

An inexpensive membrane with high proton conductivity and high fuel cell performance, which can be an alternative to Nafion for PEMFC (Proton exchange membrane fuel cell), will overcome the obstacle to widespread commercialization of fuel cells due to high cost. For this purpose, SPEEK (sulfonated polyether ether ketone)-PVA (polyvinyl alcohol) blend membranes with colloidal silica additives were synthesized in this study. Ludox AS-40 was used as the colloidal silica source and the blend membrane was prepared by solution casting method. Water uptake capacity, swelling property, size change, dynamic mechanical analysis, ion exchange capacity, AC impedance analysis, hydrolytic and oxidative stability experiments of the synthesized Ludox additives blend membranes for fuel cell application were carried out, and the membranes were also characterized by FTIR (Fourier transform infrared) analysis. While the water uptake capacities of SPEEK/PVA membranes containing 1% Ludox, 5% Ludox, and 10% Ludox at room temperature were found to be 14.08%, 14.84%, and 16.6%, respectively, the water uptake capacities at 80oC increased to 14.73%, 15.17%, and 17.11%. The proton conductivities of 1% Ludox, 5% Ludox and 10% Ludox doped SPEEK/PVA membranes at 80oC were 0.25 S/cm, 0.56 S/cm, and 0.65 S/cm, respectively. Similarly, ion exchange capacities were determined to be 1.41 meq/g, 1.63 meq/g, and 1.71 meq/g, respectively. All Ludox-added membranes exhibited excellent hydrolytic stability, retaining approximately 88% of their mass after 650 h. In addition, in oxidative stability experiments carried out in 4 ppm Fe+ 2 at 80oC, the 10% Ludox-added membrane exhibited the highest weight loss of 88.8% at the end of 24 h, while the 5% Ludox-additive membrane retained 91.6% of its total weight. Considering the proton conductivity and longevity tests of the synthesized membranes, they are thought to be promising structures. Graphical Abstract

Advances in Polyvinyl Alcohol-Based Membranes for Fuel Cells: A Comprehensive Review on Types, Synthesis, Modifications, and Performance Optimization

“…This power density was found to be similar to that of Nafion/polytetrafluoroethylene (PTFE) composite membranes, albeit marginally less than that of pristine Nafion membranes [85]. Furthermore, Yagizatli et al [86] developed an inexpensive membrane with high proton conductivity and excellent fuel cell performance as a potential alternative to Nafion for PEMFCs. Sulfonated polyether ether ketone (SPEEK) and PVA blend membranes with colloidal silica additives (Ludox AS-40) were synthesized using the solution casting method (as represented in Figure 7).…”